Since getting my PAII running I've been watching the map closely today and I'm actually becoming fascinated with it. There are several stations to the south of me scattered throughout the Dallas/Fort Worth Metroplex and today we had a light Southeasterly wind and I would watch the AQI from the stations south of me fluctuate and several minutes later mine would show the same fluctuations. I kinda visualize the pollutants as clouds that are driven by the wind.

I also get the impression that the point behind the temperature/humidity and air pressure sensors is to debunk fog and moisture related errors.

All in all I'm really enjoying the PAII. It's fun to watch the numbers change and compare with my weather station's data.

I was hoping someone who knows more about how these sensors work could help me. I have my Purpleair sensor installed and it's been working great, but there are active wildfires in my area (Southern California). When outside you can easily smell smoke but my purpleair sensor along with at least 50+ others in the area are all reading below 10 AQI. The aqmd.gov website states "In any area where you can see or smell smoke, everyone should avoid vigorous exertion and limit outdoor exposure."

Why is it that I can smell smoke but all the purpleair units are showing the air is the cleanest it's been all year?

Why is it that I can smell smoke but all the purpleair units are showing the air is the cleanest it's been all year?

I'll bet it says something about how sensitive the human sense of smell can be. Unless you're immediatly downwind of the fires you could have decent air since there seems to be a lot of air movement at the moment! Here's a Forest Service guide to estimating local air quality based on visibility. https://www.fs.fed.us/pnw/pubs/pnw_gtr925.pdf

Did someone say there are phone apps for the PurpleAir? If so what it called? My Search didn't turn up any good info which is mostly what happens..

I honestly don't know how I got this PA app on my phone, but there it is. I had been looking at the PA map in a browser a lot at the time, and one day I just saw it there! [ You are not allowed to view attachments ]

I guess the PurpleAir-II sensors are good enough. Looks like the California Air Resources Board must have done a bulk purchase back before the start of summer and the start of the fire season and got them installed.From only my sensor showing up on the PurpleAir map for my county and no other sensor around for a dozen other counties surrounding me, I am now surrounded by dozens of new sensors all with the CARB_SMOKE_XX_City Location identifier.

Now I can see dozens of new sensors all showing the smoke plumes from all the current forest fires. I think the sensor is darn good for showing particulate counts. When I good barely see my neighbors house across the street earlier, my sensor was showing the air quality as hazardous. I have been breathing bad air for over two weeks now and only go outside if it is absolutely required.

Logged

Thought I'd better join the community since I am getting a PWS tomorrow. The closest ones to my location have been very iffy in providing data to Weather Underground. I need a WU station to provide my local weather conditions for my PVOutput.org solar generation monitoring.

My Purple Air sensor is running anomalously high for PM2.5 ... for instance, today, 119 in my remote rural location while the cities are running ... 8 or less.PM10 is 52 when regionally is 1 - 2.Temp accurate, humidity accurate.

No replies from PA for over a month using Support dropdown on contact page.Ain't that special.

Might have some spiders setting up house in the sensor. Get a can of compressed air for computer cleaning and spray inside the housing liberally. Maybe dislodge whatever contamination is causing the high readings. I'm amazed that as many spiders set up shop at both my homes main door entries, I haven't had issues. My sensor is located in my front door porch alcove.

I had very high PM2.5 and PM10 readings when the smoke plumes inundated the town during July, August and midway through September. But the firefighters finally have got the upper hand in control and the air quality has returned to normal most days.

Logged

Thought I'd better join the community since I am getting a PWS tomorrow. The closest ones to my location have been very iffy in providing data to Weather Underground. I need a WU station to provide my local weather conditions for my PVOutput.org solar generation monitoring.